This invention relates to: mechanisms for moving articles along prescribed paths; harmonic drives and devices for coupling drives to article moving mechanisms; as well as to manufacturing processes which require the disposition of a plurality of articles at a work station and the removal of said articles upon completion of the work associated with the articles. More particularly this invention relates to: article moving mechanisms which incrementally index articles along a prescribed path; harmonic drives particularly adapted to operate incremental indexing mechanisms; couplings for coupling harmonic drives to indexing mechanisms; and spinning of yarn or thread from sliver.